A driving assist device has been used, which displays an image that is captured from a surrounding area of a vehicle with an on-vehicle camera on an in-vehicle monitor when parking of a vehicle or driving such as temporary retreat, for example, back-driving. A driver drives the vehicle while seeing the vehicle surrounding image displayed on the in-vehicle monitor, so that the driver is to securely recognize an obstacle. Also, the driver can accurately and easily park the vehicle in a parking zone.
As an applied technology of the driving assist device, the other image for assisting the driving is displayed with being superimposed on the vehicle surrounding image, in addition to the vehicle surrounding image captured with the on-vehicle camera.
In general, a device has been known which displays vehicle path anticipating guide lines with being superimposed on the vehicle surrounding image so as to easily recognize a distance between the vehicle and an object or a horizontal width.
For example, JP-A-2001-322519 discloses a device that calculates a turning angle of a vehicle from a difference between rotating speeds of left and right wheels of the vehicle and displays guide lines with being superimposed on a monitor in accordance with the turning angle. Thereby, a driver can easily know a steering timing, a steering amount or a retreat amount.
Also, JP-B-H2-36417 discloses a device that generates a marker signal in response to an information signal relating to a vehicle driving, including a distance between a vehicle and a surrounding obstacle, a tire steering angle and a driving speed, and displays a marker with being superimposed on a vehicle surrounding image. In this device, a marker interval is changed depending on the driving speed, for example. Thereby, it is possible to confirm an inter-vehicular distance necessary for safety driving.